ML20072G297
| ML20072G297 | |
| Person / Time | |
|---|---|
| Site: | Bellefonte  |
| Issue date: | 06/20/1983 |
| From: | Mills L TENNESSEE VALLEY AUTHORITY |
| To: | James O'Reilly NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION II) |
| References | |
| REF-PT21-83 10CFR-050.55E, 10CFR-50.55E, NUDOCS 8306280425 | |
| Download: ML20072G297 (2) | |
Text
3 L
D TENNESSEE VALLEY AUTHORITY CH ATTANOOGA. TENNESSEE 374ot 400 Chestnut Street Tower II co DC
(~Q June 20, 1983 N
5.T ao BLRD-50-438/82-45 ro BLRD-50-439/82-41 gg
.,o 0 9,.
m~
U.S. Nuclear Regulatory Commission p
3 *. '-
Region II
.r-Attn: Mr. James P. O'Reilly, Regional Administrator 101 Marietta Street, NW, Suite 2900 Atlanta, Georgia 30303
Dear Mr. O'Reilly:
BELLEFONTE NUCLEAR PLANT UNITS 1 AND 2 - B&W DESIGN OF REACTOR COOLANT SYSTEM SUPPORTS AND RESTRAINTS - BLRD-50-438/82-45, BLRD-50-439/82 FOURTH INTERIM REPORT The subject deficiency was initially reported to NRC-0IE Inspector R. V. Crlenjak on June 18, 1982 in accordance with 10 CFR 50.55(e) as NCR BLN BLP 8220. This was followed by our interim reports dated July 19, September 24, and December 20, 1982. Enclosed is our fourth interim report. We expect to submit our next report by November 18, 1983 We consider 10 CFR Part 21 applicable to this deficiency.
If you have any questions concerning this matter, please get in touch with R. H. Shell at FTS 858-2688.
Very truly yours, TENNESSEE VALLEY AUTHORITY L. M. Mills, 4anager Nuclear Licensing Enclosure cc:
Mr. Richard C. DeYoung, Director.(Enclosure)
Office of Inspection and Enforocment U.S. Nuclear Regulatory Commission Washington, D.C.
20555 Records Center (Enclosure)
Institute of Nuclear Power Operations 1100 Circle 75 Parkway, Suite 1500 Atlanta, Georgia 30339 OlylCIAL COPY 5* " 7 8306280425 830620 PDR ADOCK 05000438
/
S PDR j/,
An Equal Opportunity Employer
s ENCLOSURE BELLEFONTE NUCLEAR PLANT UNITS 1 AND 2 B&W DESIGN OF REACTOR COOLANT SYSTEM SUPPORTS AND RESTRAINTS NCR BLN BLP 8220 BLRD-50-438/82-45, BLRD-50-439/82-41 10 CFR 50.55(e)
FOURTH INTERIM REPORT Description of Deficiency The Babcock & Wilcox (B&W) design of Reactor Coolant System (RCS) supports and restraints was based on an erroneous assumption at the B&W-TVA The B&W stress report for the RCS supports and restraints interface.
assumes that the TVA-supplied embedments are of equivalent strength to the B&W-designed attachments (FY = 50 ksi). TVA-supplied embedments are of lesser strength (FY = 36 ksi). Thus, welds and shear bars at the interface points are potentially undersized and overstressed.
There have been no similar deficiencies in the past for B&W-designed l
supports and restraints.
Interim Progress Field inspection has revealed that almost all of the shear blocks have already been installed. Consequently, TVA and B&W are working together to resolve the problem by strengthening the installed configuration rather than by changing the shear block material. Increasing the weld size and/or TVA is doweling the shear blocks to the embedments is being considered.
providing detail drawings of the embedment plates to assist B&W inTVA determining if there is sufficient room to add more weld metal.
anticipates B&W completing the shear bar evaluation and submitting a revised plan for corrective action by August 1,1983 Upon receipt, TVA will review B&W's revised plan. An evaluation of the revised plan will appear in our next report.
l 4
a
_,, _ _ _ _,,,, _. _,,. _. _ _.